Lightning-arrester.



F. S. CHAPMAN. LIGHTNING ARRESTER. APPLICATION FILED D110. 24, 1912.

1,104,960. Patented July 23,191

UNITED STATES PATENT OFFICE.

FRANK SPENCER CHAPMAN. OF TOLEDO, OHIO, ASSIGrNOR TO THE NATIONALELECTRIC SPECIALTY COMPANY, OF TOLEDO, OHIO, A CORPORATION OHIO.

LIGHTNING-ARRESTER.

To all whom it may concern Be it known that I, FRANK S. CHAPMAN, acitizen of the United States, residing at Toledo, in the county of Lucasand State of Ohio, have invented certain new and useful Improvements inLightning-Arresters, of which the following is a specification.

My invention relates to lightning arresters.

One of the primary objects of the invention is to provide in a vacuumlightning arrester, that is an arrester in which the electrodes areconfined in an evacuated vessel, certain improved means for firmly andreliably fixing the electrodes in place in the vessel so that they willbe accurately and permanently spaced the required distance apart.Considerable diliiculty has been experienced, in the manufacture ofdevices of this sort, in devising means for supporting the electrodes,which are ordinarilyquite heavy in comparison with the leading-in wires,that will withstand the rough handling incident to shipment and thevibrations to which the devices are often subgreeted in use.

c The invention has for further objects such other new improvements,arrangements, constructions and devices relating to lightning arrestersas will be hereinafter more fully described and claimed.

The invention is illustrated in the accompanying drawings, wherein-Figure 1 shows an elevation of one form of lightning arrester embodyingcertain of the improvements of my invention; 2,

. a sectional view taken on line 22 of Fig. l,

parts in the several figures of the drawings.

looking in the direction of the arrows; Fig. 3, a similar view taken online 3-3 of Fig. 1; Fig.- 4, a longitudinal view of a lightning arresterutilizing a dilferent means from that shown in the preceding figures formounting the electrodes; Fig. 5, a detail view showing-in elevation andon a larger scale the devices employed for mounting and properly spacingthe electrodes one from another'in the lightning arrester shown in Fig;4; Fig. 6, a side view of the devices shown in Fig. 5. I

Like characters of reference designate like Referring first to Figs. 1to3, inclusive, 25 designates an evacuated or partially evacuatedvessel, preferably of glass and-formed preferably with an inwardlyrojecting stem Specification of Letters Patent.

Application filed December 24, 1912. Serial No. 738,430.

Patented July 28, 1914:.

26. This type of arrester is intended particularly to protect aninstrument on a me tallic circuit and hence is provided with twoelectrodes 27, :27 connected, respectively, with the line wires 28, 28and an electrode 29 which is connected with the ground wire 30. Theelectrodes 27, 27 are p referably L shaped in longitudinal section andare secured to a supporting disk 81, or some refractory non-conductingmaterial, such as porcelain, by means of screws 32 which pass throughthe horizontal lugs 33 of the electrodes and through the disk 31. Theleading-in wires 34, 3+1, which are sealed through the stem 26, areattached to the screws 32. The supporting member 31 is sustained onthese wires preferably with the aid of a body 35 of some non-conducting,plastic material such as asbestos cement. Projecting upward from thesupporting member 31., and preferably integrally formed therewith, is ashield 36 which intervenes between the electrodes 27, 27. The oppositeends 37 of the shield project above its middle portion and support in ahorizontal position the grounded electrode 29. The electrodespreferably, consist of bodies of carbon. The grounded electrode 29 ispreferably held in place by screws 38 which pass down through thesupporting disk 31 and are connected with a leading-in wire 89, alsosealed through the stem 26. By this arrangement the electrodes may beaccurately spaced one from another so as to provide spark gaps of therequired dimensions. The mounting is very secure and reliable, so thatthere is no danger that the electrodes will be displaced, either inshipment or if used in railroad switch work and subjected to thevibrations incident thereto. Furthermore, the shield 36 checks a directdis charged between the electrodes 27, 27 without interfering with thedischarge from either of the electrodes to the ground. This is desirableunder certain circumstances. This shield, however, does not prevent thedischarge between one line electrode and the grounded electrode fromionizing the gap between the other line electrode and the ground, as aspace intervenes between the shield and the grounded electrode. It isdesirable that the discharge from one line should ionize the other gapso as to reduce its resistance. It sometimes happens that when one endof the line receivesa static charge of sufficient potential to gothrough the arrester, the line on the other side of the instrument willreceive a charge heavy enough to do damage to the instrument butinsufiicient to overcome the resistance of the gap in the arrester.

In Figs. 4 to 6, inclusive, another device is employed for firmly andsecurely mounting the electrodes. The container in this case is shown asconsisting of a glass bulb similar to the ordinary incandescent electriclight bulb. The arrester has 3 electrodes, although this number might beincreased or decreased. 41, 41 designate the two line wire electrodesbetween which is arranged the grounded electrode 41". These electrodesconsist preferably of carbon plates rabbeted on their edges, as shown,and supported on the leading-in wires 42, 42, 42 which are sealedthrough the inwardly projecting stem 43 of; the container and loopedaround the rabbeted edges of their respective electrodes. The top of thestem is preferably formed with lugs 44 which intervene between adjacentelectrodes so as to keep them from being displaced at the bottom. At thetop of the electrodes a non-conducting bond is provided consistingpreferably of a shortglass rod 45 formed with bends 46 interveningbetween the outer electrodes and the middle one, the leading-in wiresbeing preferably looped around the binding device as shown in thedrawings so as to hold the same in place.

In Figs. 1 to 3, inclusive, I have shown certain preferred arrangementsand devices for mounting lightning arresters upon a switchboard orsignal box or other structure. Other arrangements than these might beemployed for accomplishing this purpose. The arrester, for example thedevice shown in Figs. 1 to 3 inclusive, is mounted in any suitablemanner on a porcelain base 47. for example, is fitted into a circularrecess 48 in one side of the base. Secured to the base 47, which will bereferred to hereafter as the removable base or base member, are U-shaped clips 49, 49 which project over the edge of the base and aresecured thereto by screws 50, 50 to which the leading-in wires 34, 34are connected. The removable base member 47 is adapted to be attached toa porcelain base member 51 which is permanently secured to theswitchboard 52 or other supporting structure, for example by means ofthe screws 53. The fixed base member 51 is provided, within recesses 54,54', with spring jacks 55, 55 consisting of strips of metal bent intoU-shape, with their extremities inturned, which are secured to the basemember 51 by screws 56, 56'. The fixed base member 51 is furtherprovided with binding posts 57, 57 connected by wires 58, 58 with thescrews 56, 56. The line wires 28,28run to these binding posts.

Secured to the removable base 47 and connected with the leading-in wire39 from the rounded electrode 26 is a stri of metal 59, ornied with anopening 60 a apting it for connection with a binding post 61, on thefixed base 51, with which is connected the ground line 30. Theconnecting strip 59 is secured to the binding post 61 by a nut 62. Itwill be seen that by these arrangements the lightning arrester can beremoved from its mounting, if necessary, for replacement r repair, veryconveniently and expeditiously, without disturbing the ground and lineconnections. The connecting piece 59 prevents the removable base membercarrying the arrester from being shaken loose from the fixed base memberbecause of vibration or other causes.

\Vhile I have described my invention in certain preferred embodiments,it will be understood that modifications might be made without departurefrom the invention.

I claim:

1. A vacuum lightning arrester comprising an evacuated vessel, threeelectrodes therein, a supporting element within the Vessel to which theelectrodes are secured and which provides a barrier intervening betweentwo of said electrodes.

2. A vacuum lightning arrester comprising an evacuated vessel, threeelectrodes therein, a supporting disk to which two of said elements aresecured, and a barrier on said disk intervening between said electrodesand supporting the third electrode.

3. A vacuum lightning arrester comprising an evacuated vessel, threeelectrodes therein, a supporting disk to which two of said electrodesare secured, a barrier between said electrodes which is higher at theends than in the middle, and means for securing the third electrode tothe projecting ends of the barrier so that a space intervenes betweensaid electrode and the middle portion of the barrier.

4:. A vacuum lightning arrester comprising an evacuated vessel, aplurality of.

leading-in wires sealed through the wall of said vessel, electrodesconnected severally with said leading-in wires, and a non-conductingclcment to rigidly hold said electrodes in proper position with respectto each other.

5. A vacuum lightning arrester comprising an evacuated glass vesselhaving an inturned stem, a base of refractory non-conducting material.one or more electrodes mounted on said base, one or more leadingin wiressealed through said stem and secured to the under side of said base andelectrically connected with said electrode or electrodes, and a body ofnon-combustible cement interposed between said stem and base.

6. A vacuum lightning arrester comprising an evacuated vessel, threeelectrodes therein, a supporting element within said vessel to whichsaid electrodes are secured and which provides a barrier interveningbetween two of said electrodes, the third electrode being arranged atone end of said bar- Tier.

7. A vacuum lightning arrester comprising an evacuated vessel, threeelectrodes in said vessel and a barrier arranged to intervene betweentwo of said electrodes, the third electrode being arranged at the end ofsaid barrier.

8. A vacuum lightning arrester comprising an evacuated vessel, two linewire electrodes and a grounded electrode therein, a supporting base towhich said line wire electrodes are secured, and a barrier on said baseintervening between said line wire electrodes and supporting atone edgethereof said grounded electrode.

10. A vacuum lightning arrester comprising an evacuated glass vesselhaving an inturned stern, a base arranged at right angles to saidstem,abarrier on said base, line wire electrodes secured to the base atopposite sides of said barrier, a grounded electrode secured to the edgeof said barrier, leading-in wires sealed through said stem and attachedto the under side of said base and electrically connected with saidelectrodes respectively, and a body of non-com bustible cementintervening between said stem and said base.

FRANK SPENCER CHAPMAN.

Witnesses:

J. S. GREENE, M. J. OGoRMAN.

